Abrasive wheel



Jan. 1, 1935. H, R SMN-DS' 1,986,648

ABRAS IVE WHEEL Original Filed Jan. 24, 1951 'F'IE E rotated at `high velocities. A

" *Herbert n.

inventionlrelates-f toabrasive wheels` and the like, and particularly to methods of balancing such wheels; `to Aprevent theirfvibrating `when Nothwithstanding numerous methods have been devised; for thepurpose ofproducing abrasive wheels that do not require balancing a large y, (percentage of the `wheels Vmade are out of balancre, 'and require Aat least some counterweighting tc balance therrrll `Balancing abrasive Wheels has .alwaysbeen a difficult problem, and` until now there has been) no :practical method, of balancing wheels other than theyusezof weights close to their taxes. y Abrasive Wheels material,` suchf as silicon carbide, or aluminous oxide, which may `be bonded with various, mavterials, such asqvitreous claysg'shellac or. synthetic `resins. Abrasive wheels are more `orless porous,

the porosity depending principallyfupon thelsize of the grains of abrasive material `used,. `the smallerlthe `grainsy the `less the porosity. While myI invention is applicable to `wheels of other i grades, it is more particularly adapted to balancing wheels of `low porosity.

I shall now `describe my invention in detail,A

with the aid of the accompanying drawing, in which: i

Fig. 1 depicts an (abrasive wheel of a well known form, balanced by my method, and

Fig. 2 is a view of the wheel looking directly` at its edge. d

For the purposes of this application I shall call the flat surfaces of the Wheel, indicated at 10-10,

the faces of the wheel, and the periphery 11 willl becalled its edge. `At its center the wheel is pro-` vided with a bushing 14, usually made of lead. As methods of determining which is the light and which theheavy side of a wheel, and for determining when the wheel isin balance, are

well known, it is not necessary to describe any such method. Having determined that the dot 12 near the edge of the wheel in Fig. 1 marks the i center of gravity of the light side of the wheel,

, indicated by the dot 12, inthe center. Then I give the sectors a coat of paint, indicated at 13. The term "paintf is here usedin abroad sense; that is, meaning incrusting or covering the surface with a hard coatof material which will are made of `granular abrasive ENroFFiCc."

,adhereA thereto. `'Ihere `are `various-` paintsfand varnishes that can be used for this purpose, but

l,I prefer a varnish made of `a gum-resin reduced to fluidity With` naphtha. In Fig. 2 this coating is `shovvn somewhat exaggerated in thickness.

l, After the paint has dried I give the entireface, 1or\faces,\of the wheel a `uniform coatof paint. This isnot necessary, however, as` it merely conceals the painted sectors `and improves the appearance of` the Wheel. l

The purpose of painting crease the Weight of `the light side-to equality with the weight of the heavy side, and thereby thesectorsis to inbalance the wheel. The final coat, being"V uniform over-the whole facial surface, does not `upset the y;

balance. The size of the `painted sector may be varied according to the amount of` weight itis tneeded I make the `sector proportionately small- ,erI While there` are numerous paintsandyarimportant to use only such as contain nothing which might affect the bonding material in the wheel.

`As is well known, abrasive Wheels are mounted f on shafts which are rotated at high velocities,

and a Wheel is usually clamped between a face plate, rigidly fixed to the shaft, and a loose plate of the same diameter as the fixed plate, the latter plate being forced toward thefixed plate by .a

nut screwed on the shaft. While the sectors are not ordinarily as thick as they are shown inf Fig. 2, they do have some thickness. The thickness of the sectors, like their area, may be varied according to the amount of weight it is necessary to add'to the light side of the Wheel. One way lof doing this is to vary the consistency of the paint. Another way is to apply a plurality of coats of `paint in the sectoral areas.` As the sectors might, because of their thickness, prevent the properseating of the clamping plates, and even tilt the Wheel and cause it to wabble, I prefer to curtail the sectors so they do not extend under the plates. This is illustrated in Fig. 1, where the dotted circle 15 indicates the position of the periphery of a clamping plate. It will be seen that at itsrinner edge the sector 13 misses the circle `15 and it would not interfere with proper seating of the clamping plate. Of course, if

of balancing Wheels is especially applicable to y Wheels of low porosity. In my pending application, Serial No. 509,694 I havevdescribed and claimed a method of balancing abrasive Wheels which consists in introducing some substance into the pores of the Wheel on the light side of its axis. That method-isespecially adapted-.touseon wheels of high-porosity; that is, Wheels with largegpores or foramina. Insaid application I have also claimed an abrasive Wheel which is Ybalanced.byA

somesubstance lodged in its pores. In the practice of the present method there may be :more for less absorption of the paint into ,the rinterior f the wheel, depending upo'rr the absorb'tiv' y(porosity) ofthe Wheel and the consistence ofjtlie paint, and the paint absorbed becomes apart o f the counterweight. Butas some Wheels rare'jso unabsorptive as to permit of little ornopenetra-` tion of paint applied to its exterior,;thc .present invention depends principally upon the Weight of lthe paintremaining ontheout'side ofthe wheel in Clneoflthe advantages of balancing lWheels -by .the-present method -is that the Wheels remain in Ibalanceas they gradually become smaller through Wear.' While-I have only described my invention in connection withan ordinarystraight Wheel itislplainthat theinvention is applicable to Wheels of otherls'hape's. If the amount of IvQfeight-need'ed to balance a Wheel is determined by sticking a lump o'fclay or-other material tothe edge ofthe *Wheelit -Willifrequire more Weight in the sectors `lenabl himfto balance the Wheel inthe first treatment, and he will seldom have to resort to a second treatment.

Having fully described my invention and the preferred manner of practicing it, I claim:

1. An abrasive Wheel which is balanced by a sectoral coat of paint'applied to one or both faces on the-light side of thewheeh f 12. An abrasive 'Wheelvhichysiszbalanced by a sectoral coat of paint applied to one or both faces lon the light side of the Wheel, said coats of paint lb'eingcurtailed on their inner ends on a line farther from the axis of the Wheel than will be the A.peripheries of clamping plates used in mounting fthe'vvheel onfashaft.'

QM 3p-An. abrasive vvheel which is balanced with paint app-lied to a sectoral area of one or both l'facesori'the -1ight-side of the Wheel, a portion of said'p'aint Lbeing in the pores of the Wheel and a portionibeing on the facial surface thereof.

4. An abrasive Wheel which is balanced with paintappliedto a sectoral'area of one orboth Afaces on the klight side of the wheel, a small portion of saidpaint being in thepores of the Wheel, but the greater portion being on the facial surfacethereof. Y `5. vAn abrasive Wheel of low porosity which isbalanced with paint applied to a limited area lof one or both .faces of the Wheel, on its light side, the `major portion of the :paint being on theiacial surfaceaof the Wheeli `6. -An-abrasive Wheelvvhichis balanced with a ,coatof-paintapplied ina limited area of oner or Ib'othfaces,on1its light side.

'7. An abrasive wheel which is balanced by a sectoral coat of somelsubstance applied ina liquid Vstateto one or both faces on the 'light side of the Wheel.

8. Anabrasive wheel Whichis'balanced yWith a `coatof some-substance applied in a liquid state to a limite'darea of one or bothfaces, on its light side.

HERBERTRSIMQNDS. 

